Exchange of trace gases between soils and the atmosphere in scots pine forest ecosystems of the northeastern German lowlands. 1. Fluxes of N₂O, NO/NO₂ and CH₄ at forest sites with different N-deposition

This study summarizes the results obtained from measurements of the exchange rates of N$_{2}$O–N, NO–N, NO$_{2}$–N and CH$_{4}$ between Scots pine forest soils of the northeastern German lowlands and the atmosphere in the years 1995–1998. In order to further identify the effects of atmospheric N-deposition on the magnitude of N- and C-trace gas fluxes, five Scots pine forest sites with different loads of atmospheric N-input (15–22 kg N ha$^{−1}$ per year) were investigated. The measurements show an increase in NO and N$_{2}$O fluxes at the higher N-affected sites (mean values, NO: 21–39 $\mu$g NO–N m$^{−2}$ h$^{−1}$, N$_{2}$O: 16–32 $\mu$g N$_{2}$O–N m$^{−2}$ h$^{−1}$) as compared to the sites with moderate atmospheric N-input (mean values, NO: 3–9 $\mu$g NO–N m$^{−2}$ h$^{−1}$, N$_{2}$O: 5–10 $\mu$g N$_{2}$O–N m$^{−2}$ h$^{−1}$). ... mehrIn addition, it could be demonstrated that atmospheric N-deposition did not only effect N-trace gas fluxes at our study sites, but also the magnitude of atmospheric CH$_{4}$-uptake by the forest soils, since at the pine forest sites with moderate atmospheric N-deposition CH$_{4}$uptake rates were approximately two- to five-fold higher (mean values: −140 to −165 $\mu$g CH$_{4}$ m$^{−2}$ h$^{−1}$) than at the sites with high atmospheric N-input (−24 to −77 $\mu$g CH$_{4}$ m$^{−2}$ h$^{−1}$).

This study summarizes the results obtained from measurements of the exchange rates of N$_{2}$O–N, NO–N, NO$_{2}$–N and CH$_{4}$ between Scots pine forest soils of the northeastern German lowlands and the atmosphere in the years 1995–1998. In order to further identify the effects of atmospheric N-deposition on the magnitude of N- and C-trace gas fluxes, five Scots pine forest sites with different loads of atmospheric N-input (15–22 kg N ha$^{−1}$ per year) were investigated. The measurements show an increase in NO and N$_{2}$O fluxes at the higher N-affected sites (mean values, NO: 21–39 $\mu$g NO–N m$^{−2}$ h$^{−1}$, N2O: 16–32 $\mu$g N$_{2}$O–N m$^{−2}$ h$^{−1}$) as compared to the sites with moderate atmospheric N-input (mean values, NO: 3–9 $\mu$g NO–N m$^{−2}$ h$^{−1}$, N$_{2}$O: 5–10 $\mu$g N$_{2}$O–N m$^{−2}$ h$^{−1}$). ... mehrIn addition, it could be demonstrated that atmospheric N-deposition did not only effect N-trace gas fluxes at our study sites, but also the magnitude of atmospheric CH$_{4}$-uptake by the forest soils, since at the pine forest sites with moderate atmospheric N-deposition CH$_{4}$uptake rates were approximately two- to five-fold higher (mean values: −140 to −165 $\mu$g CH$_{4}$ m$^{−2}$ h$^{−1}$) than at the sites with high atmospheric N-input (−24 to −77 $\mu$g CH$_{4}$ m$^{−2}$ h$^{−1}$).